Found only in the darkest recesses of the Grid, code worms are used very effectively by the likes of Gorn and Lomox to erase or rewrite information on identity discs. When mishandled, however, their use can result in physical and mental damage to programs subjected to their effects.

Code worms are about a handspan long, and have a flat segmented body, ten to twelve sets of jointed legs behind two large pincers, a blue glowing circular maw which takes up their entire front end, and a long, smooth, luminous segment at its tail end from which two bright antennae sweep out behind them. When carrying a payload, they are entirely translucent and luminescent. Code worms can be handled, albeit with caution, by their bulbous tails. They are introduced into identity discs via the code-copy of the victim's head, entering through the eye and causing considerable pain as they do their work.

Trivia

Code worms, like computer worms, their real-world namesakes, carry a payload (in this case, an implantable false memory or an instruction to purge a memory) into their host in order to compromise it.

They share some similarities with gridbugs, although gridbugs are better known for destroying code while code worms can manipulate it.